We have one wire of resistance `R_1` and it is stretched to n times its initial length to change its resistance to `R_2` calculate `R_2//R_1` .

Explanation

To solve the problem of finding the ratio \( \frac{R_2}{R_1} \) when a wire of resistance \( R_1 \) is stretched to \( n \) times its initial length, we can follow these steps:

### Step 1: Understand the relationship between resistance, length, and area
The resistance \( R \) of a wire is given by the formula:
\[ R = \frac{\rho L}{A} \]
where:
...